Adipogenesis in Rodent Skin, The Dermal Adipose Layer: What Signals Adipocyte Development in the Lower Dermis?

Research into adipogenesis has become increasingly more fundamental as our understanding of diabetes and obesity develops. Adipose tissue (fat) exists in many depots throughout the body. While widely known that there is a subcutaneous adipose depot beneath the skin, more recently a separate dermal adipose layer, within the lower dermis of rodent skin, has been found. However, the developmental origins and timings of adipogenesis in this dermal layer are not well characterised. This thesis aims to study adipogenesis within this layer, by creating an in vivo-like model and investigating signalling pathway effects. Firstly, the hypothesis of an inhibition signal from the upper dermis and the role of the G0/G1 switch gene 2 (G0S2) in the dermal adipose tissue was explored. Experiments showed G0S2 expression in the lower dermis during development. PPARγ has been shown as a main regulator of adipogenesis, together with C/EBPα. The potential role of PPARγ in early adipogenesis was investigated, using immunofluorescence analysis. Microarray analysis studies previously showed molecular differences between in vitro and in vivo, therefore model systems, more closely related to in vivo conditions, are necessary. An organ culture and a cell culture model were developed. The cell culture model, using 3D cell spheres, proved most useful to investigate signalling in adipocyte development. The EGF/EGFR, TGFβ/BMP and KGF/KGFR pathways were studied, by supplementing cultures with an activator or inhibitor of the receptor of each pathway. Differential levels of oil red O staining and therefore adipocyte formation, were observed. In conclusion, this work was found to suggest commitment of the cells to the adipocyte lineage begins earlier, than from when microarray data was collected. While not conclusive, it provides an insight and direction for further studies, in terms of PPARγ and potential adipogenic inhibition signals in the upper dermis, as well as a model system

Powder interlayer bonding of geometrically complex Ti-6Al-4V parts

Powder interlayer bonding (PIB) is a novel joining technique, which has been developed to facilitate high integrity repairs of aerospace components, manufactured from commonly used Titanium alloys. The technique utilises an interlayer between complex geometric components which are mated under pressure and a highly localised heating source. In this study, induction heating enabled bonding in an inert fusion zone by use of an oxygen displacing shielding gas, with particular attention to the initial heating and pressure application. These early stages proved crucial to the elimination of pores and consolidation of the alloy powder, with porosity volume fraction reduced to just 0.5% after just 20 seconds at the bonding force. The technique has produced high integrity bonds in alloys such as Ti-6Al-4V, retaining approximately 90% of the alloy strength in previous studies, offering advantages over established joining methods such as tungsten inert gas (TIG) and plasma arc (PA) welding due to a more highly localised heating and fusion zone. It is believed that powder interlayer bonding can compete against these techniques, providing a more time and cost effective repair route for net shape components manufactured from a range of alloys with minimal post processing

Automated detectionof very low surface brightness galaxiesin the Virgo cluster

We report the automatic detection of a new sample of very low surface brightness (LSB) galaxies, likely members of the Virgo cluster. We introduce our new software, {\tt DeepScan}, that has been designed specifically to detect extended LSB features automatically using the DBSCAN algorithm. We demonstrate the technique by applying it over a 5 degree$^2$ portion of the Next-Generation Virgo Survey (NGVS) data to reveal 53 low surface brightness galaxies that are candidate cluster members based on their sizes and colours. 30 of these sources are new detections despite the region being searched specifically for LSB galaxies previously. Our final sample contains galaxies with $26.0\leq\langle \mu_{e}\rangle\leq28.5$ and $19\leq m_{g}\leq21$, making them some of the faintest known in Virgo. The majority of them have colours consistent with the red sequence, and have a mean stellar mass of $10^{6.3\pm0.5} M_{\odot}$ assuming cluster membership. After using {\tt ProFit} to fit S\'ersic profiles to our detections, none of the new sources have effective radii larger than 1.5 Kpc and do not meet the criteria for ultra-diffuse galaxy (UDG) classification, so we classify them as ultra-faint dwarfs.Comment: 16 pages, 14 figures, Accepted for publication in MNRAS 201

The relationship between perceived organisational ethical climate and employee commitment in the Australian hospitality industry

The purpose of this study was to determine the relationship between perceived organisational ethical climate and employee commitment within an Australian hospitality organisation, with the objective of determining whether employees' perceptions of the organisational ethical climate influenced their commitment towards their organisation, as well as the associated implications. The Ethical Climate Questionnaire and the Employee Commitment Survey were utilised as measuring instruments. The overall finding revealed a statistically significant relationship between the two variables with the results indicating that organisations possess numerous ethical climates which are perceived by employees in a manner which in turn affects their commitment towards their organisation. It is concluded that employees who are more committed to their organisations have improved attendance records and show lower absenteeism and turnover rates. The findings of this study confirmed existing research and generated new knowledge applicable to the hospitality sector.Industrial and Organisational PsychologyM. Com. (Industrial and Organisational Psychology

An assessment of the African Union mission in Somalia's role in conflict transformation in Somalia.

Master of Social Science in Psychology. University of KwaZulu-Natal, Durban 2016Somalia has experienced protracted conflict since 1991. A number of peace enforcement operations were undertaken to bring stability to the country but they encountered difficult conditions resulting to the withdrawal of peacekeeping forces. Following the struggle for control of Somalia among armed groups, countries closer to Somalia were forced to intervene because their security was threatened. During this period, there was a continental arrangement to conduct peace operations in Africa. As a result, an African Union (AU) Peace Support Operations (PSOs) was deployed in Somalia. The mission called the African Union Mission in Somalia (AMISOM) came at a time when Somalia had undergone a series of peace and reconciliation conferences, and had to ensure that the activities of armed groups was curbed in order to bring stability to Somalia. Although the mission has faced a significant number of challenges, it is important to take note of its achievements. AMISOM has managed to recruit peacekeepers from a range of African countries to fight against the militant group called Al-Shabaab. In March 2011 it started a military campaign to support the then Transitional Federal Government (TGF) forces to retake Mogadishu and the whole of Somalia from Al-Shabaab. This initiative illustrates that the mission is making an effort to articulate and push the extension of state authority in Somalia, in an effort to bring stability to the state. Given the prospect of the mission to succeed, it is important that the root causes are addressed in order to avoid a relapse into violent conflict. This research employs the use of conflict transformation theory, to assess AMISOM’s contribution to Somalia’s conflict transformation, by looking at transformative elements or activities that are addressing the root causes of the conflict. The use of this theoretical argument will help to determine the extent to which AMISOM has contributed to Somalia’s conflict transformation. AMISOM is the lead player in transforming the conflict. It is important for the mission to analyse its role; its successes; to reflect on gaps; and redesign approaches. This may be required so that a relapse into violence may be avoided. The aim of the research therefore is to examine AMISOM’s contribution to ending the conflict in Somalia, with reference to its role in addressing the root causes of the conflict directly or indirectly as its implements its mandate. The main objectives of the research are to examine AMISOMs contribution to ending the conflict in Somalia, identify initiatives which AMISOM can undertake to transform the conflict and provide concrete recommendations on the role of AMISOM in transforming the conflict in Somalia. At the end of the study, the research finds that AMISOM has brought some amount of stability to Mogadishu, where ordinary populations are conducting businesses on normal basis. The research also finds that the mission’s activities are largely focused on counter- insurgency strategies; the expansion of Somalia’s state authority, capacity building of security forces, civil service, and the protection of the government

Powder Interlayer Bonding of Nickel-Based Superalloys with Dissimilar Chemistries

Novel joining methods are crucial for the aerospace industry to repair components damaged in the high stress, high cycle environment of the jet turbine engine. Powder interlayer bonding (PIB) is a novel joining technique that is being explored for use in the aerospace industry. PIB involves the use of a powder interlayer between two faying surfaces alongside a localised temperature gradient and compressive force to produce one joined workpiece. The use of a localised temperature gradient not only reduces the heat affected zone (HAZ) but also reduces the energy requirements for the process as only a small area of the component needs to be elevated in temperature. Nickel-based superalloys are commonly used in the gas turbine engine due to their superior mechanical properties that are maintained even under the most elevated temperatures experienced in the jet turbine engine. It is therefore essential these alloys can be easily repaired. Conventional joining methods such as friction welding have proved difficult for new generation nickel-based superalloys; therefore, there is much interest in PIB as an alternative repair technology. This study shows the potential of PIB to join dissimilar nickel-based superalloys: bonds with very little porosity were observed after only a short processing time

The Effect of Processing Variables on Powder Interlayer Bonding in Nickel-Based Superalloys

Powder Interlayer Bonding (PIB) has been considered as a lower-energy joining technology for nickel-based superalloys compared to conventional methods; such as friction welding. Typically; nickel-based superalloys exhibit high energy requirements for joining due to their high operating temperatures. However; PIB utilizes a localized temperature gradient created by an induction current; reducing the energy requirements for the process. PIB is a solid-state joining method that compresses and heats a powder interlayer between two faying surfaces to produce one joined workpiece. It has been successfully used to bond titanium alloys; and the objectives of this work were to explore its application as a joining method for nickel-based superalloys. Initial results showed that joining nickel-based superalloys via PIB is possible; and bondlines with very little porosity were observed. Further analysis showed that these bonded areas had lower porosity than the base material; suggesting PIB could be a successful joining method for difficult-to-join nickel-based superalloys

Virologic failure and second-line antiretroviral therapy in children in South Africa--the IeDEA Southern Africa collaboration

Article approval pendingWith expanding pediatric antiretroviral therapy (ART) access, children will begin to experience treatment failure and require second-line therapy. We evaluated the probability and determinants of virologic failure and switching in children in South Africa

Growth of HIV-exposed uninfected infants in the first 6 months of life in South Africa: The IeDEA-SA collaboration

BACKGROUND: HIV-exposed uninfected (HEU) infants are a growing population in sub-Saharan Africa especially with the increasing coverage of more effective prevention of mother-to-child transmission (PMTCT) antiretroviral therapy regimens. This study describes the characteristics of South African HEU infants, investigates factors impacting birth weight and assesses their growth within the first 28 weeks of life. METHODS: This is a retrospective cohort based on routine clinical data from two South African PMTCT programmes. Data were collected between 2007 and 2013. Linear regression assessed factors affecting birth weight-for-age z-scores (WAZ) while growth (longitudinal WAZ) was assessed using mixed effects models. RESULTS: We assessed the growth of 2621 HEU infants (median birth WAZ was -0.65 (IQR -1.46; 0.0) and 51% were male). The feeding modalities practised were as follows: 0.5% exclusive breastfeeding, 7.9% breastfeeding with unknown exclusivity, 0.08% mixed breastfeeding and 89.2% formula feeding. Mothers with CD4 <200 cells/μl delivered infants with a lower birth WAZ (adjusted ß -0.253 [95% CI -0.043; -0.072], p = 0.006) compared to mothers with aCD4 ≥500 cells/μl. Similarly, mothers who did not receive antiretroviral drugs delivered infants with a lower birth WAZ (adjusted ß -0.39 [95% CI -0.67; -0.11], p = 0.007) compared to mothers who received antenatal antiretrovirals. Infants with a birth weight <2 500g (ß 0.070 [95% CI 0.061; 0.078], p <0.0001) experienced faster growth within the first 28 weeks of life compared to infants with a birth weight ≥2 500g. Infants with any breastfeeding exposure experienced slower longitudinal growth compared to formula fed infants (adjusted ß -0.012 [95% CI 0.021; -0.003], p = 0.011). CONCLUSION: Less severe maternal disease and the use of antiretrovirals positively impacts birth weight in this cohort of South African HEU infants. Formula feeding was common with breastfed infants experiencing marginally slower longitudinal growth